Use of antibodies in lymphocyte secretions for detection of subclinical tuberculosis infection in asymptomatic contacts

Clin Diagn Lab Immunol. 2004 Nov;11(6):1022-7. doi: 10.1128/CDLI.11.6.1022-1027.2004.


We have previously demonstrated that Mycobacterium bovis BCG-specific immunoglobulin G antibodies in lymphocyte secretions (ALS) can be employed as a marker for active tuberculosis (TB). We aimed to determine whether the ALS method allows detection of subclinical TB infection in asymptomatic individuals. A prospective study of family contacts (FCs) of patients with active TB and healthy controls was performed. Thirteen of 42 FCs had high ALS responses, including 6 FCs who subsequently developed active TB. No correlation was observed between the tuberculin skin test and the ALS responses in the FCs (r = 0.1, P = 0.23). Among patients with active TB, BCG-specific ALS responses steadily declined from the time of diagnosis through 6 months following antimycobacterial chemotherapy (P = 0.001). The ALS assay enabled detection of infection in exposed symptom-free contacts, who are at greater risk for developing active TB. The method may also allow discrimination between effective treatment of active infection and suboptimal response to therapy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antibodies, Bacterial / analysis*
  • Antibodies, Bacterial / immunology
  • Antigens, Bacterial / immunology*
  • Cells, Cultured
  • Immunoglobulin G / analysis*
  • Immunoglobulin G / immunology
  • Lymphocytes / immunology*
  • Mycobacterium bovis / immunology*
  • Mycobacterium tuberculosis / immunology*
  • Predictive Value of Tests
  • Sputum / cytology
  • Sputum / immunology*
  • Tuberculosis, Pulmonary / diagnosis*
  • Tuberculosis, Pulmonary / pathology


  • Antibodies, Bacterial
  • Antigens, Bacterial
  • Immunoglobulin G